1. Field of the Invention
The present invention relates to respiratory patient interface systems, and, in particular, to a respiratory patient interface device including a modular frame member and dual chamber nasal pillows assembly.
2. Description of the Related Art
There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, which varies with the patient's respiratory cycle, to treat a medical disorder, such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA), or congestive heart failure.
Non-invasive ventilation and pressure support therapies involve the placement of a patient interface device including a mask component on the face of a patient. The mask component may be, without limitation, a nasal mask that covers the patient's nose, a nasal cushion that rests beneath the patient's nose (such as a “pillows” style nasal cushion having nasal prongs that are received within the patient's nares or a “cradle” style nasal cushion that rests beneath and covers the patient's nares), a nasal/oral mask that covers the nose and mouth, or a full face mask that covers the patient's face. The patient interface device interfaces the ventilator or pressure support device with the airway of the patient through tubing, so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient. It is known to maintain such devices on the face of a wearer by a headgear having one or more straps adapted to fit over/around the patient's head.
Patient interface devices that have a mouth cushion and nasal pillows, for example, are typically constructed with the pillows forming a part of the mouth cushion. Accordingly, the flow of gas generated by the ventilator or pressure support device enters into a single chamber. In other words, there is no way to effectively and efficiently customize the patient interface device, for example, by allowing various sizes and combinations of pillows and/or mouth cushions to be installed and employed to provide a customized, enhanced fit for the patient.